Multi-tiered interface between conductor rod and work machine

ABSTRACT

A work machine, such as a hauler at a mining site, includes a conductor rod housing concentric metal tubes for receiving electrical power from a contactor sliding on a power rail. A head-end interface of the conductor rod proximate the work machine includes multiple tiers to which terminal connectors are affixed. The tiers are at different heights above the base of the head-end interface, providing a distance or spacing between adjacent terminal connectors, thus reducing the need to increase a diameter of head-end interface to accommodate adjacent terminal connectors.

TECHNICAL FIELD

The present disclosure relates to an interface between a conductive rodand a work machine. More specifically, the present disclosure relates toan interface having multiple tiers upon which electrical connectors areinstalled for interfacing with a work machine, and to an electricallypowered work machine coupled electrically and pneumatically to theconductive rod.

BACKGROUND

Heavy work machines, such as earth-moving vehicles or hauling trucks,require significant power to carry out their functions. The machinesthemselves can be of substantial weight, and their loads require largeamounts of power to move. Diesel engines typically provide that power,but they can have disadvantages. For instance, in some implementations,heavy work machines may need to travel large distances through ruggedterrain. At a remote mining site, for example, groups of these machinesare often employed to ferry extreme loads along roadways, or haulroutes, extending between various locations within the mining site.Supplies of diesel fuel may be far away from such locations or noteasily delivered to such locations. In addition, the groups of dieselmachines can generate significant pollution.

Electrical power has been used to supplement these diesel engines whilethe work machines move. In some environments, the electrical power isdelivered from wires over the haul route to a pantograph on the workmachine as the machine travels the haul route, as in a cable car. Butoverhead wires cannot reliably provide sufficient electrical energy topower a heavy work machine during long movements. Nor can the overheaddelivery provide enough current to charge backup batteries for anelectric machine at the same time. As a result, electrical power throughoverhead wires typically supplements, rather than replaces, dieselengines in heavy work machines.

Alternatively, a power rail based on the ground may provide electricalpower to heavy work machines. An axially moveable cylindrical rodincludes at one end an interface with the work machine and at anopposite end a connection with the power rail at the side of a haulroute, for example. In some situations, the interface with the workmachine not only provides electrical power from the rod to the workmachine, but also passes pressurized air from the work machine into therod for energizing pneumatic controls. In addition, signaling data mayneed to be passed between the rod and the work machine for electricalsensors or controls. Accommodating these interfaces in a cylindrical rodhandling high-voltage electrical power can be challenging.

One approach for providing electrical power through a rod to a travelingvehicle is described in International Patent App. Pub. No. WO2009/007879A2 (“the '879 application”). The '879 application describes ahybrid transport system in which a rechargeable hybrid vehicle, in someembodiments, has contactors made of round or rectangular tubes that canextend from either side of the vehicle to connect with a metal stripalong a roadside providing electrical power. While the contactors can bemaneuvered with hydraulic or pneumatic cylinders, the cylinders aredistinct from the contactors and can cause the contactors to pivotoutwardly from the vehicle about axles. As a result, the contactorsdescribed in the '879 application are prone to disconnection from theroadside metal strips, thereby causing temporary interruptions in theflow of electrical power from the metal strips to the vehicle. Suchinterruptions are undesirable, and may not be permissible in manyworksite applications. In particular, the system of the '879 applicationis not suited for use with machines, such as construction machines,mining machines, paving machines, and the like, requiring relativelyhigh-voltage electrical power for propulsion and other functions.

Examples of the present disclosure are directed to overcomingdeficiencies of such systems.

SUMMARY

In an aspect of the present disclosure, an apparatus for conductingelectrical energy includes a rigid outer tube with a first end, a secondend, an outer diameter, and a longitudinal center defining an axisbetween the first end and the second end. A first conductor within therigid outer tube includes a first metal tube surrounding and extendingalong the axis from proximate the first end to the first metallicendplate and a first metallic endplate having a first longitudinalthickness extending orthogonally from the first metal tube to the outerdiameter. A second conductor includes a second metal tube concentricallysurrounding and separated from the first metal tube by an annular spaceand a second metallic endplate. The second metal tube extends fromproximate the first end to the second metallic endplate, while thesecond metallic endplate has a second longitudinal thickness extendingorthogonally from the second metal tube to the outer diameter. Thesecond metallic endplate is farther from the second end than the firstmetallic endplate.

In another aspect of the present disclosure, a conductor assemblyincludes a first conductor and a second conductor. The first conductorincludes a first conductive tube and a first conductive annulus, wherethe first conductive tube surrounds and extends along a longitudinalaxis from a distal end to the first conductive annulus and the firstconductive annulus has a first longitudinal thickness extending radiallyfrom the first conductive tube to an outer diameter. The secondconductor includes a second conductive tube and a second conductiveannulus, where the second conductive tube is concentrically inside thefirst conductive tube and extends from the distal end to the secondconductive annulus. The second conductive annulus has a secondlongitudinal thickness extending radially from the second conductivetube to the outer diameter, and the second conductive annulus is fartherfrom the distal end than the first conductive annulus.

In yet another aspect of the present disclosure, a work machine includesan electric engine, a battery, traction devices configured to causemovement of the work machine when powered by the electric engine, and aconductor rod having a first end and second end and configured to conveyelectrical energy to the work machine during the movement of the workmachine. The conductor rod has a rigid outer tube with an outer diameterand a longitudinal center defining an axis between the first end and thesecond end. The conductor rod further includes tubular conductors,successively arranged concentrically around the axis and separated, atleast in part, by air, and metallic rings. The metallic rings areattached respectively to terminations of the tubular conductorsproximate the first end, and individual ones of the metallic ringsextend orthogonally from corresponding ones of the tubular conductors tothe outer diameter and are spaced apart along the axis.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an isometric view of a work machine within an XYZcoordinate system as one example suitable for carrying out theprinciples discussed in the present disclosure.

FIG. 2 illustrates a longitudinal section of a conductor rod with an armdisposed in a barrel, in accordance with one or more examples of thepresent disclosure.

FIG. 3 is a longitudinal cross-sectional view of a conductor rod and aconnector assembly, in accordance with one or more examples of thepresent disclosure.

FIG. 4 is an isometric view of a head-end interface having multipletiers, in accordance with one or more examples of the presentdisclosure.

FIG. 5 is an isometric cross-sectional view of a portion of a conductorrod with head-end interface, along the cut lines shown in FIG. 4 , inaccordance with one or more examples of the present disclosure.

FIG. 6 is a flowchart depicting a method of powering a work machine froma moveable conductor rod using multi-tier head-end interface, inaccordance with one or more examples of the present disclosure.

FIG. 7 is a partial isometric rear view of a conductive rod and head-endinterface in accordance with an example of the present disclosure.

FIG. 8 is an isometric view of a longitudinal section of the conductiverod and connector of FIG. 8 in accordance with an example of the presentdisclosure.

FIG. 9 is a flowchart depicting a method of powering a work machine froma moveable conductive rod in accordance with an example of the presentdisclosure.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughoutthe drawings to refer to same or like parts. FIG. 1 illustrates anisometric view of a work machine 100 within an XYZ coordinate system asone example suitable for carrying out the principles discussed in thepresent disclosure. The exemplary work machine 100 travels parallel tothe X axis along a roadway, also termed a haul route 101, typically froma source to a destination within a worksite. In one implementation asillustrated, work machine 100 is a hauling machine that hauls a loadwithin or from a worksite within a mining operation. For instance, thework machine 100 may haul excavated ore or other earthen materials froman excavation area along haul route 101 to dump sites and then return tothe excavation area. In this arrangement, work machine 100 may be one ofmany similar machines configured to ferry earthen material in a trolleyarrangement. While a large mining truck in this instance, work machine100 may be any machine that carries a load between different locationswithin a worksite, examples of which include an articulated truck, anoff-highway truck, an on-highway dump truck, a wheel tractor scraper, orany other similar machine. Alternatively, work machine 100 may be anoff-highway truck, on-highway truck, a dump truck, an articulated truck,a loader, an excavator, a pipe layer, or a motor grader. In otherimplementations, work machine 100 need not haul a load and may be anymachine associated with various industrial applications including, butnot limited to, mining, agriculture, forestry, construction, and otherindustrial applications.

Referring to FIG. 1 , an example work machine 100 includes a frame 103powered by electric engine 102 to cause rotation of traction devices104. Traction devices 104 are typically four or more wheels with tires,although tracks or other mechanisms for engagement with the ground alonghaul route 101 are possible. Electric engine 102 functions to providemechanical energy to work machine 100 based on an external electricalpower source, such as described in further detail below. An example ofmechanical energy provided by electric engine 102 includes propellingtraction devices 104 to cause movement of work machine 100 along haulroute 101, but electric engine 102 also includes components sufficientto power other affiliated operations within work machine 100. Forinstance, in some implementations, electric engine 102 includesequipment for converting electrical energy to provide pneumatic orhydraulic actions within work machine 100. While electric engine 102 isconfigured to operate from an external electrical power source, electricengine 102 typically includes one or more batteries for storingelectrical energy for auxiliary or backup operations.

In accordance with the principles of the present disclosure, andrelevant to the presently disclosed subject matter, the work machine 100further includes a conductor rod 106 configured to receive electricalpower from a power rail 108. In some examples, power rail 108 is one ormore beams of metal arranged substantially parallel to and a distanceabove the ground. In FIG. 1 , power rail 108 is positioned to besubstantially parallel to the X axis and the direction of travel of workmachine 100. Support mechanisms hold power rail 108 in place along adistance at the side of haul route 101 for work machine 100 to traverse.The support mechanisms and power rail 108 may be modular inconstruction, enabling their disassembly and reassembly at differentlocations or their repositioning along the existing haul route 101.Moreover, while shown in FIG. 1 to the left of work machine 100 from theperspective of an operator sitting in the cab of the work machine 100,power rail 108 may be disposed to the right of work machine 100 or inother locations suitable to the particular implementation.

Power rail 108 provides a source of electrical power for work machine100 as either AC or DC. In some examples, power rail 108 has two or moreconductors, each providing voltage and current at a different electricalpole. In one implementation (e.g., an implementation in which the powerrail 108 includes three conductors), one conductor provides positive DCvoltage, a second conductor provides negative DC voltage, and a thirdconductor provides 0 volts relative to the other two conductors. The twopowered conductors within power rail 108 provide +1500 VDC and −1500VDC. These values are exemplary, and other physical and electricalconfigurations for power rail 108 are available and within the knowledgeof those of ordinary skill in the art Further, it should be understoodthat the voltages described herein are merely exemplary, as variouslevels of AC voltage may be used, as well as a combination of AC and DCvoltages, depending on the particular configuration.

Conductor rod 106 enables electrical connection between work machine 100and power rail 108, including during movement of work machine 100 alonghaul route 101. In the example shown in FIG. 1 , conductor rod 106 is anelongated arm resembling a pole. FIG. 1 shows conductor rod 106positioned along a front side of work machine 100, with respect to thedirection of travel of work machine 100 in the direction of the X axis.In this arrangement, conductor rod 106 is located in FIG. 1 in the Y-Zplane essentially along the Y axis with a first end 107 near a rightside of work machine 100 and a second end 111 at a left side of workmachine 100. Conductor rod 106 may be attached to any convenientlocation within work machine 100, such as to frame 103, in a manner tocouple conductor rod 106 to power rail 108. Shown in FIG. 1 as extendingto a left side of work machine 100 toward power rail 108, conductor rod106 may alternatively be arranged to extend to a right side and at anydesired angle from work machine 100 such that conductor rod 106 may becoupled to power rail 108 for obtaining electrical power.

As embodied in FIG. 1 , conductor rod 106 includes a barrel 109 mountedto frame 103 of work machine 100. Barrel 109 has a hollow interior andmay be a conductive metal having suitable mechanical strength andresiliency, such as aluminum. Within barrel 109, an arm 110 is retained.Arm 110 is engaged within conductor rod 106 along the Y axis in FIG. 1 .A length of conductor rod 106 roughly spans the width of work machine100. A junction 112 serves as the junction or interface between arm 110and barrel 109, which is the main body of conductor rod 106. When arm110 is fully retracted or collapsed into barrel 109, junction 112essentially becomes the left edge of conductor rod 106. On the otherhand, when arm 110 is extended from barrel 109 of conductor rod 106, arm110 may reach from work machine 100 to proximate power rail 108 on theside of haul route 101.

Within, and possibly including barrel 109, conductor rod 106 includes aseries of electrical conductors passing longitudinally, at least from ahead 122 at a proximal end of the conductor rod 106 to a tip 124 at adistal end of the conductor rod 106. Typically, the conductors withinconductor rod 106 are formed of a metallic material and are rigid. Insome examples, the conductors are concentric tubes, or hollow cylinders,of solid metal such as copper, aluminum, gold, silver, nickel, zinc, oralloys thereof nested together and sized to provide electrical capacitysufficient for powering work machine 100. Other conductive materials maybe used, such as graphite, and are considered to be within the scope ofthe presently disclosed subject matter. Tubular conductors within arm110 engage with corresponding tubular conductors within barrel 109 toprovide for electrical continuity. In other examples, one or moreconcentric copper tubes, rather than aluminum, of varying diameters maybe used as tubular conductors. Other types of conductive tubes may beused and are within the scope of the presently disclosed subject matter.

At tip 124, a connector assembly 114 provides an interface to power rail108 via trailing arms 116 and contactor 118. Power rail 108 is typicallyarranged along a side of haul route 101, and work machine 100 is steeredso that it traverses haul route 101 substantially in parallel with powerrail 108. Thus, in reference to FIG. 1 , power rail 108 and a travelpath for work machine 100 are substantially in parallel with each otherand with the X axis. Contactor 118 is configured to maintain anelectrical connection with power rail 108 while sliding along itssurface in the direction of the X axis as work machine 100 moves. Insome examples, trailing arms 116 are conductors coupled to contactor118, each conducting voltage and current at a different electrical poleand corresponding to the conductors within conductor rod 106. Inoperation, electrical power is accessed from power rail 108 viacontactor 118, which remain in contact during movement of work machine100, and the electrical power is conducted through trailing arms 116into connector assembly 114.

From connector assembly 114, the electrical power is conveyed at tip 124through the nested tubular conductors within arm 110 and barrel 109 tohead 122 of conductor rod 106 and through a head-end interface 120 towork machine 100. Head-end interface 120 provides at least an electricalconnection between conductor rod 106 and work machine 100 for poweringelectric engine 102 and otherwise enabling operations within workmachine 100. In some examples, head-end interface 120 may also providean interface for inputs to control mechanical operation of conductor rod106.

As noted above, the tubular or cylindrical nature of conductor rod 106,lending to a degree of rigidity greater than a solid conductor ofsimilar or smaller mass or weight to conductor rod 106 due to a largermoment of inertia of a hollow tube than a solid rod of similar mass.Thus, by forming the conductive material into a hollow tube rather thana solid rod, for similar conductive performance, conductor rod 106 canprovide a mechanism to conduct electrical power from a source to a loadover an unsupported distance. As described above, trailing arms 116 areconductors coupled to contactor 118, each conducting voltage and currentat a different electrical pole and corresponding to the conductorswithin conductor rod 106. Different cylindrical conductors withinconductor rod 106 can provide for the transmission of differentelectrical potentials along conductor rod 106, illustrated in moredetail in FIG. 2 , below.

FIG. 2 illustrates a longitudinal cross-section of a section ofconductor rod 106 with arm 110 disposed in barrel 109, in accordancewith one or more examples of the present disclosure. More specifically,FIG. 2 depicts a longitudinal cross-section of a section of conductorrod 106 between head-end interface 120 and connector assembly 114, fromhead 122 to tip 124, when viewed facing in the direction of travel forwork machine 100, i.e., in the direction of the X axis along. Thus,conductor rod 106 lies in the Y-Z plane, as indicated in FIG. 2 .

Referring to the right side of FIG. 2 , barrel 109 contains anarrangement of concentric conductors of tubular shape, i.e., as hollowcylinders. In this example, from an axial center AB outward, firstcylinder conductor 202 is positioned concentrically along axial centerAB (i.e. the longitudinal axis of barrel 109) of barrel 109 and is atubular conductor made of aluminum or a similar metal with highelectrical conductivity and high mechanical strength. For instance, analuminum alloy such as 6061-T6 may be used for first cylinder conductor202 and other conductive tubes in conductor rod 106. Other suitablemetals or alloys thereof may be used and are considered to be within thescope of the presently disclosed subject matter. In some examples, firstcylinder conductor 202 has an outer diameter of approximately 3.5 inchesto 4.5 inches. However, it should be understood that dimensions providedherein are merely for purposes of illustration and are not intended tobe limitations, as dimensions described in relation to variouscomponents may be greater or less than the examples provided herein.First cylinder conductor 202 begins at head 122 and extends axiallyalong conductor rod 106 around axial center AB to a barrel end 205. As atube, first cylinder conductor 202 defines first cylinder cavity 204within inner surface 207 of first cylinder conductor 202. If arm 110were removed from barrel 109 in FIG. 2 , first cylinder cavity 204 wouldbe an open, inner space within first cylinder conductor 202 from head122 to barrel end 205. In one example, first cylinder cavity 204 has adiameter of about 2.5 to 3 inches.

A second cylinder conductor 206 is positioned concentrically along axialcenter AB and surrounds first cylinder conductor 202. As with firstcylinder conductor 202, second cylinder conductor 206 is a tubularconductor made of aluminum or a similar metal with high electricalconductivity and high mechanical strength. Second cylinder conductor 206is similarly positioned around a Y axis within FIG. 2 and spans adistance from head 122 to barrel end 205. In one example, secondcylinder conductor 206 has an outer diameter of about 5 inches to 5.5inches. These dimensions, as well as other dimensions discussed below,are merely examples and could be greater or lesser than the statedvalues. Being arranged concentrically around and, by definition, havinga larger diameter than first cylinder conductor 202, second cylinderconductor 206 forms a radial gap between it and first cylinder conductor202. In the example of FIG. 2 , that gap is filled by second cylinderinsulation 208, which is an insulation comprised of a closed cellpolyurethane foam. Other types of materials for second cylinderinsulation 208 that provide electrical insulation and lightweightsupport within conductor rod 106 will be available and apparent to thoseof ordinary skill in the field. In some examples, second cylinderinsulation 208 has a thickness of about 1.5 inches to 0.75 inches.

In some examples, second cylinder insulation 208 can be a dielectric.Dielectric materials can be solids, liquids, or gases. Some solids canbe used as dielectrics, such as porcelain, glass, plastics, and theclosed cell polyurethane foam described above. In configurations inwhich a cylinder conductor or piston conductor is hermetically sealed onboth ends of the cylinder conductor or piston conductor, fluidicdielectrics can be used in gaps, such as radial gap around firstcylinder conductor 202 and second cylinder conductor 206. Fluiddielectrics can include some forms of oil or gaseous dielectrics such asair, nitrogen, helium, and other dry gases such as sulfur hexafluoride.In further configurations in which a cylinder conductor or pistonconductor is hermetically sealed on both ends of the cylinder conductoror piston conductor, a partial vacuum can be used. In various examples,a partial vacuum can be used as a nearly lossless dielectric even thoughits relative dielectric constant is unity. It should be noted that thedielectrics disclosed herein are merely examples, as other dielectricsmay be used and are considered to be within the scope of the presentlydisclosed subject matter. Different dielectrics can be used in variousradial gaps of conductor rod 106 to allow for different voltages anddifferent types of electrical potentials to be conducted by conductorrod 106. A partial vacuum can be created by pulling air from within aconductor rod, such as from within a cavity, explained in more detail inFIG. 7 .

Moving farther out radially on the right side of FIG. 2 , third cylinderconductor 210 is positioned concentrically along axial center AB andsurrounds second cylinder conductor 206 and first cylinder conductor202. Third cylinder conductor 210 is a tubular conductor made ofaluminum or a similar metal with high electrical conductivity and highmechanical strength. As with the other tubes discussed, third cylinderconductor 210 extends from head 122 to barrel end 205 within conductorrod 106. In one example, third cylinder conductor 210 has an outerdiameter of about 8 to 9 inches. A third cylinder cavity 212 betweensecond cylinder conductor 206 and third cylinder conductor 210 is anopen space, which, if arm 110 were removed from barrel 109 in FIG. 2 ,would form a tubular cavity extending from head 122 to barrel end 205.

Concentrically along axial center AB and around third cylinder conductor210 and the other tubular conductors, fourth cylinder conductor 214forms an outer conductive path from head 122 to barrel end 205.Similarly, fourth cylinder conductor 214 is a tubular conductor made ofan aluminum alloy or a similar metal with high electrical conductivityand high mechanical strength. In one example, fourth cylinder conductor214 has an outer diameter of about 14 inches. A gap 215 defined as aspace between outer surface 217 of third cylinder conductor 210 and aninner surface 219 of fourth cylinder conductor 214, in some examples, isabout 0.75 inches and is filled with fourth cylinder insulation 216,which is a closed cell polyurethane foam, dielectric, or similarsubstance.

Radially beyond fourth cylinder conductor 214, a covering or barrelshell 218 encases conductor rod 106. Barrel shell 218 is typically ametal or similar substance providing structural integrity to conductorrod 106. Barrel shell 218 has an inner diameter in excess of an outerdiameter of fourth cylinder conductor 214. As a result, a retractioncavity 220 of a tubular shape is formed between fourth cylinderconductor 214 and barrel shell 218 that extends from head 122 to barrelend 205. A stop 222, which is part of a housing for conductor rod 106 atjunction 112, defines a longitudinal end for retraction cavity 220 awayfrom head 122.

The various annular or tubular cavities within barrel 109, namely, firstcylinder cavity 204, third cylinder cavity 212, and the head end ofretraction cavity 220 (barrel shell cavity 242, described below), aresealed or capped by the attachment of head-end interface 120 to theirends at head 122. The attachment of head-end interface 120 is designedto provide an airtight (or hermetic) seal within these cavities, forpurposes to be understood further below.

Viewing FIGS. 1 and 2 together, arm 110 is a substantially cylindricalbody having an outer diameter D1 that is smaller than inner diameter D2of barrel shell 218, allowing arm 110 to slidable engage into barrel109. As well as providing a longitudinal end for retraction cavity 220,stop 222 also defines an inner diameter D3 through which arm 110 slides,as shown to the left of FIG. 2 . By sliding, it is meant that arm 110may move longitudinally along the Y axis within barrel 109 as arm 110 ismoved axially with respect to conductor rod 106, from left to right inFIG. 2 for retraction and from right to left in FIG. 2 for extension.The result of the sliding is the increase or decrease in the overalllength of conductor rod 106 via arm 110, as illustrated in FIG. 1 .

Referring now to the left side of FIG. 2 , arm 110 also contains aseries of concentric conductors of cylindrical or tubular shape. In thisexample, from the axial center outward, first piston conductor 224 ispositioned at a center of arm 110 and is, as with the other tubularconductors of arm 110, made of a metal such as aluminum 6061-T6 orsimilar substance having high electrical conductivity and highmechanical strength. First piston conductor 224 extends from tip 124 toan arm end 225, shown at the right side of FIG. 2 . Being tubular, firstpiston conductor 224 has a first piston cavity 226 within its innerdiameter that is filled with air or another gas. A second pistonconductor 228 concentrically surrounds first piston conductor 224 andextends from tip 124 to arm end 225. Second piston conductor 228 is madeof a conductive material, and in some examples has an inner diameter ofbetween about 5 and 6 inches. A space defined as second piston cavity230 is formed between the inner diameter of second piston conductor 228and the outer diameter of first piston conductor 224, which is leftunfilled other than with air or a similar gas.

Moving radially outward from second piston conductor 228, a third pistonconductor 232 axially centered on the Y axis concentrically surroundssecond piston conductor 228. Similarly made of a conductive material,third piston conductor 232 is set off radially from second pistonconductor 228 a distance of less than 1 inch, which is filled with athird piston insulation 234. As with second cylinder insulation 208 andfourth cylinder insulation 216, third piston insulation 234 can be aclosed cell polyurethane foam or comparable substance providingelectrical insulation and lightweight stability. An arm shell 236 ofconductive material such as metal concentrically surrounds third pistonconductor 232 from tip 124 to about arm end 225. In some examples, armshell 236 has an outer diameter of about 11.625 inches. Within an innerdiameter of arm shell 236, an arm shell cavity 238 of free space existsbetween arm shell 236 and third piston conductor 232.

In some examples, the outer surface of arm shell 236 includes gasket240, which serves to stably set apart arm shell 236, and arm 110generally, from barrel shell 218. As illustrated in FIG. 2 , as arm 110is retracted or extended within barrel 109, gasket 240 separatesretraction cavity 220 from a barrel shell cavity 242. As well, gasket240 can help retain arm 110 within conductor rod 106 in a state ofmaximum extension by butting against stop 222.

As illustrated, FIG. 2 represents an arrangement in which conductor rod106 essentially has two longitudinal halves. It should be noted,however, that a conductor rod of the presently disclosure does notrequire multiple halves, illustrated in FIG. 3 , below. Returning toFIG. 2 , a first half, barrel 109, on the right side of FIG. 2 ,includes barrel shell 218 enclosing a series of tubular cylinderconductors aligned along the Y axis. Those cylinder conductors, viewedradially from axial center AB, are first cylinder conductor 202, secondcylinder conductor 206, third cylinder conductor 210, and fourthcylinder conductor 214. Within that concentric arrangement, tubularregions of open space exist within first cylinder cavity 204 and thirdcylinder cavity 212. Further, barrel shell 218 encases barrel 109 andforms an open space 244 within retraction cavity 220 and barrel shellcavity 242. On the left side of FIG. 2 , arm 110 includes arm shell 236enclosing a series of tubular piston conductors also aligned along axialcenter AB of conductor rod 106. Those piston conductors, viewed radiallyfrom axial center AB, are first piston conductor 224, second pistonconductor 228, and third piston conductor 232. Within that concentricarrangement, tubular regions of open space exist within first pistoncavity 226 and second piston cavity 230. Further arm shell 236 encasesarm 110 and forms an open space 246 within arm shell cavity 238.

In an operating state for conductor rod 106, arm 110 is inserted intobarrel 109 to form a nested configuration of the piston conductors andthe cylinder conductors. For example, when arm 110 is inserted intobarrel 109, the outer surface 227 of first piston conductor 224 fitswithin an internal space formed by an inner surface 229 of firstcylinder conductor 202. During operation, first piston conductor 224maintains electrical contact with first cylinder conductor 202,permitting electrical conductivity between those tubular conductors.When first piston conductor 224 is mated within first cylinder conductor202, first piston cavity 226 and first cylinder cavity 204 connectivelyextend axially through conductor rod 106 from head 122 to tip 124.

Similarly, when the combination of second piston conductor 228, thirdpiston conductor 232, and interposed third piston insulation 234 areslid as part of arm 110 into barrel 109, an outer surface 231 of thirdpiston conductor 232 fits within an inner surface 233 of third cylinderconductor 210, and an inner surface 235 of second piston conductor 228fits over an outer surface 237 of second cylinder conductor 206. As aresult, second piston conductor 228, third piston conductor 232, andthird piston insulation 234 are disposed in the empty space defined bythird cylinder cavity 212. In this configuration, third piston conductor232 electrically contacts third cylinder conductor 210, and secondpiston conductor 228 electrically contacts second cylinder conductor206. In some examples, and as shown similarly in FIG. 2 , when conductorrod 106 is fully collapsed, at least some volume of empty space willremain within third cylinder cavity 212, which will have an annular ortubular shape and be defined radially by portions of second cylinderconductor 206 and third cylinder conductor 210.

Conversely, when arm 110 is inserted into barrel 109, the cylinderconductors will be disposed within cavities within the piston from leftto right in FIG. 2 , and the cylinder conductors are nested with thepiston conductors. For example, the combination of first cylinderconductor 202, second cylinder conductor 206, and second cylinderinsulation 208 are in the open space defined by second piston cavity 230within arm 110, during which, as mentioned, first cylinder conductor 202electrically contacts first piston conductor 224 and second cylinderconductor 206 electrically contacts second piston conductor 228.Likewise, in the illustrated example, the sandwich of third cylinderconductor 210, fourth cylinder conductor 214, and fourth cylinderinsulation 216 are in the open space defined by arm shell cavity 238within arm 110. Third cylinder conductor 210 will contact third pistonconductor 232, and fourth cylinder conductor 214 will do the sameagainst arm shell 236.

As mentioned above, head-end interface 120 provides at least anelectrical connection between conductor rod 106 and work machine 100 forpowering electric engine 102 and otherwise enabling operations withinwork machine 100. Head-end interface 120 also provides the physicalsecurement of first cylinder conductor 202, second cylinder conductor206, third cylinder conductor 210, and fourth cylinder conductor 214 towork machine 100, allowing arm 110 to extend and retract in relation toconductor rod 106, illustrated in more detail in FIGS. 3 and 4 , below.

FIG. 3 is a longitudinal cross-sectional view of a conductor rod 300 onthe side of a tip 324 proximate to connector assembly 312, in accordancewith one or more examples of the present disclosure. For purposes ofsimplicity, only the side of conductor rod 300 proximate to connectorassembly 312 is illustrated, though the technologies and techniquesdescribed in FIG. 3 and below are applicable to conductor rod 300proximate to a head-end interface, such as head-end interface 120 ofFIGS. 1 and 2 . FIG. 3 depicts a longitudinal cross-sectional of aportion of conductor rod 300 when viewed facing in the direction oftravel for a work machine, such as work machine 100 of FIG. 1 , i.e., inthe direction of the X axis. Thus, conductor rod 300 lies in the Y-Zplane, as indicated in FIG. 3 . Conductor rod 300 includes firstcylinder conductor 302, second cylinder conductor 304, third cylinderconductor 306, and barrel 308. Conductor rod 300 includes connectorassembly 312. Similar to the conductor rod 106 of FIG. 1 , connectorassembly 312 is located proximate to a power supply to conduct powerfrom the power supply to work machine 100 (or load).

First cylinder conductor 302, second cylinder conductor 304, and thirdcylinder conductor 306 are concentric conductors of tubular shape, i.e.as hollow cylinders. In FIG. 3 , from axial center CD outward, firstcylinder conductor 302 is positioned at a center of barrel 308. Secondcylinder conductor 304 concentrically surrounds first cylinder conductor302. As with first cylinder conductor 302, second cylinder conductor 304is a tubular conductor made of aluminum or a similar metal with highelectrical conductivity and high mechanical strength. Second cylinderconductor 304 is similarly positioned concentrically around axial centerCD. Moving farther out radially, third cylinder conductor 306concentrically surrounds second cylinder conductor 304 and firstcylinder conductor 302. Concentrically around third cylinder conductor306 and the other tubular conductors, barrel 308 forms an outerconductive path. In some examples, barrel 308 can act as a fourthcylinder conductor if constructed from a conductive material. Firstcylinder conductor 302, second cylinder conductor 304, third cylinderconductor 306, and barrel 308 span a distance from head-end interface310 to connector assembly 312. Radially beyond fourth cylinder conductor214, barrel 308 encases conductor rod 300. Barrel 308 is typically ametal or similar substance providing structural integrity to conductorrod 300. However, in some examples, barrel 308 is a non-conductivematerial that isolations the electrically energized interior ofconductor rod 300 from an environment. Barrel 308 has an inner diameterin excess of an outer diameter of fourth cylinder conductor 214.

As tubes, first cylinder conductor 302 defines first cylinder cavity 314within inner surface 315 of first cylinder conductor 302, secondcylinder conductor 304 defines second cylinder cavity 316 between innersurface 317 of second cylinder conductor 304 and outer surface 319 offirst cylinder conductor 302, third cylinder conductor 306 defines thirdcylinder cavity 318 between inner surface 321 of third cylinderconductor 306 and outer surface 323 of the second cylinder conductor304, and barrel 308 defines fourth cylinder cavity 320 between innersurface 325 of barrel 308 and outer surface 327 of the third cylinderconductor 306. First cylinder cavity 314, second cylinder cavity 316,third cylinder cavity 318, and/or fourth cylinder cavity 320 can befilled with insulative materials such as closed cell polyurethane foam.In other examples, first cylinder cavity 314, second cylinder cavity316, third cylinder cavity 318, and/or fourth cylinder cavity 320 arefilled with a dielectric. Dielectric materials can be solids, liquids,or gases. Some solids can be used as dielectrics, such as porcelain,glass, plastics, and the closed cell polyurethane foam described above.In configurations in which a cylinder conductor is hermetically sealedon both ends of conductor rod 300, fluidic dielectrics can be used incavities, First cylinder cavity 314, second cylinder cavity 316, thirdcylinder cavity 318, and/or fourth cylinder cavity 320. Fluiddielectrics can include some forms of oil or gaseous dielectrics such asair, nitrogen, helium, and other dry gases such as sulfur hexafluoride.In further configurations in which a cylinder conductor or pistonconductor is hermetically sealed on both ends of the cylinder conductoror piston conductor, a partial vacuum can be used. In various examples,a partial vacuum can be used as a nearly lossless dielectric even thoughits relative dielectric constant is unity. It should be noted that thedielectrics disclosed herein are merely examples, as other dielectricsmay be used and are considered to be within the scope of the presentlydisclosed subject matter.

Different dielectrics can be used in various cylinder cavities ofconductor rod 300 to allow for different voltages and different types ofpotentials to be conducted by conductor rod 300. For example, firstcylinder conductor 302 and second cylinder conductor 304 can beconfigured to conduct a DC voltage and third cylinder conductor 306 canbe configured to conduct an AC voltage. Because both first cylinderconductor 302 and second cylinder conductor 304 are conducting DCvoltage, there may be no need or requirement to have a dielectric otherthan air between first cylinder conductor 302 and second cylinderconductor 304. However, if the AC voltage being carried on thirdcylinder conductor 306 is of a certain voltage level or frequency, adielectric of suitable strength can be used to prevent a short betweensecond cylinder conductor 304 and third cylinder conductor 306.

The various annular or tubular cavities within barrel 308, namely, firstcylinder cavity 314, second cylinder cavity 316, third cylinder cavity318, and/or fourth cylinder cavity 320, are sealed or capped by theattachment of the ends of the cylinder conductors to an interface. InFIG. 3 , the interface is connector assembly 312, though the sametechnology and techniques can be used to attach the other ends ofcylinder conductors to another interfaces, such as head-end interface120 of FIG. 2 . The attachment is designed to provide an airtight (orhermetic) seal within these cavities. For example, when using fluidicinsulative materials or dielectrics, or a partial vacuum, a hermeticseal maintains the fluid within the particular cavity to which the fluidis inserted, or, maintains the partial vacuum from which the air waspumped out. To provide for an airtight seal, the ends of the cylinderconductors can be affixed to interfaces using various technologies,including welding, glue, adhesive, gaskets, and the like. To removablyaffix the ends of the cylinder conductors, whereby the ends can beinstalled, removed, and reinstalled, the cylinder conductors can use aterminal connector assembly. The terminal connector assemblies use athreaded member inserted into a terminal receiver. The terminal receiveris affixed to a respective cylinder conductor, thereby providing foraffixing and removing the cylinder conductors from either a head-endinterface, such as head-end interface of FIGS. 1 and 2 , or connectorassembly 312.

In FIG. 3 , first cylinder conductor 302 is affixed to head-endinterface 310 using terminal connector assembly 330 and threaded members332A and 332B. Threaded members 332A and 332B are inserted throughhead-end interface 310 and into terminal connector assembly 330. Secondcylinder conductor 304 is affixed to head-end interface 310 usingterminal connector assembly 360A and 360B and threaded members 346A and346B. Threaded members 346A and 346B are inserted through head-endinterface 310 and into terminal connector assembly 360A and 360B. Thirdcylinder conductor 306 is affixed to head-end interface 310 usingterminal connector assembly 362A and 362B and threaded members 348A and348B. Threaded members 348A and 348B are inserted through head-endinterface 310 and into terminal connector assembly 362A and 362B. Barrel308 is affixed to head-end interface 310 using terminal connectorassembly 364A and 364B and threaded members 350A and 350B. Threadedmembers 350A and 350B are inserted through head-end interface 310 andinto terminal connector assembly 364A and 364B.

In FIG. 3 , threaded members 332A/332B, 346A/346B, 348A/348B, and/or350A/350B are used to provide electrical power from their respectiveconductor cylinders to a load, such as work machine 100. It is notedthat threaded members 350A and 350B may provide electrical power or maybe connected to a ground, such as work machine 100. However, asillustrated in FIG. 3 , threaded members 332A/332B, 346A/346B,348A/348B, and/or 350A/350B are disposed substantially along the sameplane or the Z axis. In some examples, however, threaded members may bedisposed on different planes of a head-end connector, as illustrated byexample in FIG. 4 .

FIG. 4 is an isometric view of a head-end interface 400 having multipletiers, in accordance with one or more examples of the presentdisclosure. Head-end interface 400 is within an XYZ coordinate system.Head-end interface 400 can be used as head-end interface 120 of FIG. 1 .Head-end interface 400 may be constructed of various types of materials,including metals, ceramics, and plastic. If constructed of a metal,head-end interface 400 may be coated with an insulative material toprevent electrical shorts. Head-end interface 400 includes structuralfeatures that enable electrical connection with a conductor rod, such asconductor rod 300 of FIG. 3 , using threaded members. Head-end interface400 provides access for passing electrical power from a conductor rod toa work machine, such as work machine 100. Head-end interface 400 isshown illustrated with threaded members 402A and 402B, 404A and 404B,406A and 406B, and 408A and 408B. Threaded members 402A and 402, 404Aand 404B, 406A and 406B, and 408A and 408B are constructed in a mannersimilar to threaded members of FIG. 3 . Threaded member 408A is shown inFIG. 4 as being partially extracted from head-end interface 400. Asillustrated in FIG. 4 , load 437 can receive electrical power throughelectrical connector 434 connected to head-end interface 400 by threadedmember 408A. Load 437 can also receive electrical power throughelectrical connector 436. In some examples, if threaded member 408A isconnected to a barrel or outer tube, rather than being connected to load437, electrical connector may be connected to a ground.

Head-end interface 400 includes one or more tiers, for example tiers410-416, that are disposed above each other longitudinally along the Zaxis, which in FIG. 4 , are generally circular in shape. Head-endinterface 400 includes a central axis GT that extends through the centerof head-end interface 400 in the direction of the Z axis. Tier 410 isdefined by a substantially planar surface 418 extending substantiallyperpendicular to the central axis GT. The tier 410 also includes a risersection 420 extending substantially perpendicularly from the surface418. The riser section 420 comprises a substantially cylindrical outerwall of the tier 410, and the central axis GT extends substantiallycentrally through the surface 418 and the riser section 420. As shown inFIG. 4 , the tier 410 has an axial height A as measured from the surface418 to a substantially planar surface 422 of the tier 412. In someexamples, the height A of the tier 410 comprises an axial height of thesubstantially cylindrical riser section 420. Tier 412 is defined by asubstantially planar surface 422 extending substantially perpendicularto the central axis GT. The tier 410 also includes a riser section 424extending substantially perpendicularly from the surface 422. The risersection 424 comprises a substantially cylindrical outer wall of the tier412, and the central axis GT extends substantially centrally through thesurface 422 and the riser section 424. As shown in FIG. 4 , the tier 412has an axial height B as measured from the surface 422 to asubstantially planar surface 426 of the tier 414. In some examples, theheight B of the tier 412 comprises an axial height of the substantiallycylindrical riser section 424. Tier 414 is defined by a substantiallyplanar surface 426 extending substantially perpendicular to the centralaxis GT. The tier 414 also includes a riser section 428 extendingsubstantially perpendicularly from the surface 426. The riser section428 comprises a substantially cylindrical outer wall of the tier 414,and the central axis GT extends substantially centrally through thesurface 426 and the riser section 428. As shown in FIG. 4 , the tier 414has an axial height C as measured from the surface 426 to asubstantially planar surface 430 of the tier 416. In some examples, theheight C of the tier 414 comprises an axial height of the substantiallycylindrical riser section 428. In some examples, height A, height B, andheight C are substantially the same or similar. In other examples,height A, height B and/or height C can be different from each other.

Threaded members 402A and 402 are located on tier 410. Threaded members404A and 404B are located on tier 412. Threaded members 406A and 406Bare located on tier 414. Threaded members 408A and 408B are located ontier 416. Head-end interface 400 is shown with bore 438. Bore 438 is anannular space 439 in head-end interface 400 that extends throughhead-end interface 400 and provides an opening through head-endinterface 400 into which fluids such as air may be introduced orremoved. Bore 438 cylindrical structure extending substantiallyperpendicularly from surface 418 along axis GT, 438. Bore 438 throughannular space 439 is a channel extending substantially centrally throughhead-end interface 400 formed by the structure to some other location(not shown). For example, bore 438 may be used to deliver pressurizedair within a conductor rod. In some examples, the pressurized airprovides an axial force that can affect a movement of a conductor rod.

Head-end interface 400 provides for a multi-tier interface to whichcylinder conductors may be affixed. Threaded members can be physicallyand electrically connected to respective conductive cylinders totransfer electrical energy received from a power source, through one ormore piston conductors and cylinder conductors, and into theirrespective terminal connectors, illustrated by way of example in FIG. 5, which uses head-end interface 400 connected to conductor rod 300 ofFIG. 3 .

FIG. 5 is an isometric cross-sectional partial view of a conductor rod500 with head-end interface 400 along the cut lines shown in FIG. 4revealing internal conductors, as discussed below, in accordance withone or more examples of the present disclosure. Head-end interface 400is physically and electrically connected to conductor rod 300 of FIG. 3. Threaded members 402A and 402B are located on tier 410. Threadedmembers 404A and 404B are located on tier 412. Threaded members 406A and406B are located on tier 414. Threaded members 408A and 408B are locatedon tier 416. Conductor rod 500 includes first cylinder conductor 502,second cylinder conductor 504, third cylinder conductor 506, and barrel508. First cylinder conductor 502, second cylinder conductor 504, thirdcylinder conductor 506, and barrel 508 are mechanically affixed tohead-end interface 400. Conductor rod 500 further includes first pistonconductor 512, second piston conductor 514, third piston conductor 516,and arm 518.

In some examples, tier 416 has a diameter D1 through axial length FGdefined by the substantially cylindrical riser section 428 and/or by thesubstantially planar surface 430 (FIG. 4 ), tier 414 has a diameter D2through axial length FG defined by the substantially cylindrical risersection 428 and/or by the substantially planar surface 426 (FIG. 4 )that is less than diameter D1, tier 412 has a diameter D3 through axiallength FG defined by the substantially cylindrical riser section 424and/or by the substantially planar surface 422 (FIG. 4 ) that is lessthan diameter D1 and diameter D2, and tier 410 has a diameter D4 throughaxial length FG defined by the substantially cylindrical riser section420 and/or by the substantially planar surface 418 (FIG. 4 ) that isless than diameter D1, diameter D2, and diameter D3.

An inner surface 568 of first cylinder conductor 502 concentricallysurrounds and is slidably engaged with an outer surface 570 of firstpiston conductor 512 from radius HI along axial length FG. An innersurface 572 of second piston conductor 514 concentrically surrounds isslidably engaged with an outer surface 574 of second cylinder conductor504 from radius HI along axial length FG. Third cylinder conductor 506concentrically surrounds third piston conductor 516 from radius HI alongaxial length FG. Barrel 508 concentrically surrounds arm 518 from radiusHI along axial length FG. First piston conductor 512, second pistonconductor 514, third piston conductor 516, and arm 518 are insertableinto and retractable from first cylinder conductor 502, second cylinderconductor 504, third cylinder conductor 506, and barrel 508. Firstcylinder conductor 502 is mechanically affixed to internal surface 564of head-end interface 400 tier 410 by threaded members 402A and 402Bextending from an outer surface 566 of head-end interface 400 thruinternal surface 564 and into first cylinder conductor 502. Secondcylinder conductor 504 is mechanically affixed to internal surface 564of head-end interface 400 tier 412 by threaded members 404A and 404Bextending from outer surface 566 of head-end interface 400 thru internalsurface 564 and into second cylinder conductor 504. Third cylinderconductor 506 is mechanically affixed to internal surface 564 ofhead-end interface 400 tier 414 by threaded members 406A and 406Bextending from outer surface 566 of head-end interface 400 thru internalsurface 564 and into third cylinder conductor 506. Barrel 508 ismechanically affixed to internal surface 564 of head-end interface 400tier 416 by threaded members 408A and 408B extending from outer surface566 of head-end interface 400 thru internal surface 564 and into barrel508. In use, if the outermost tube, barrel 508 acts as a rigid outertube of conductor rod 500.

Piston conductors 512-516 and arm 518 are in electrical and physicalcommunication with their respective cylinder conductors 502-506 andbarrel 508 via one or more conducting interfaces. For example, aconducting interface 528 comprises a contacting interface between anexterior contacting surface 529 of arm 518 and an interior contactingsurface 531 of barrel 508. Conducting interface 528 provides both aslidable physical interface as well as an electrical interface betweenbarrel 508 and arm 518. Acting as an electrical interface, electricalpower is transferred from piston conductors 512-516 to their respectivecylinder conductors 502-506, allowing for the continuous transfer ofelectrical power while the conductor rod 500 extends and retracts.Various technologies may be used to provide for a physical andelectrical interface. Arm 518 extends and retracts by sliding along theconducting interface 528, maintaining a physical and electricalinterface. In FIG. 5 , the interface is head-end interface 400, thoughthe same technology and techniques can be used to attach pistonconductors 512-516 to connector assembly 114 of FIG. 1 using threadedmembers. The attachment is designed to provide an airtight (or hermetic)seal within these cavities.

Another example of a conducting interface is conducting interface 530.Rather than direct contact between a cylinder conductor and a pistonconductor acting as an electrical and physical interface, conductinginterface 530 uses carbon brushes, such as brush 532. Brush 532 is asolid material formed from a conductive material, such as carbon orgraphite, that provides both a physical and electrical interface betweensecond cylinder conductor 504 and second piston conductor 514. Brush 532may be formed by compacting a mix of materials such as carbon, graphite,and metallic power (e.g. copper) into a solid piece of material sizedand shaped to be used in conducting interface 530.

Another example of an electrical interface material that provides forthe conduction of electrical power from a piston conductor to a cylinderconductor is a metallic alloy that is liquid at a certain temperature,such as room temperature. An example of a metallic alloys is GALINSTAN.GALINSTAN is a eutectic alloy composed of gallium, indium, and tin whichmelts at −19 C (−2 F) and is thus liquid at room temperature. It shouldbe noted, however, that other metal allows with properties similar toGALINSTAN may be used and are considered to be within the scope of thepresently disclosed subject matter.

In order to keep a metallic alloy at an interface, the metallic alloywill be contained within a space enclosed by the surfaces of the pistonconductor and the cylinder conductor in which the liquid alloy is beingused. For example, conducting interface 534 is a space defined by aninterior surface 539 of first cylinder conductor 502 and an exteriorsurface 541 of first piston conductor 512. Conducting interface 534 isconfigured to act as a fluidic barrier, reducing or eliminatingpotential leaks of the liquid metallic alloy contained therein intoother areas of the conductor rod 500. As first piston conductor 512extends and retracts within first cylinder conductor 502, conductinginterface 534 with a liquid metallic alloy contained therein provide fora constant electrical connection between first cylinder conductor 502and first piston conductor 512.

During use, the conducting interface 534 may be filled with additionalliquid metallic alloy. FIG. 5 illustrates one manner in which this maybe accomplished, though other technologies for filling or refillingconducting interface 534 with additional liquid metallic alloy may beused and are considered to be within the scope of the presentlydisclosed subject matter. In FIG. 5 , to introduce a liquid metallicalloy into conducting interface 534, piston channel 536, and interfacechannel 538 are used. To introduce a liquid metallic alloy intoconducting interface 534, conductor rod 500 is in a retractedconfiguration so that first piston conductor 512 abuts or nearly abutsinterface channel 538 so that interface channel 538 is in liquidcommunication with piston channel 536. Terminal connector 520 isremoved, creating a fluidic input bore 537 extending through thehead-end interface 400 providing for interface channel 538 to extendfrom an outer surface 559 of head-end interface 510 to piston channel536. The liquid metallic alloy can be introduced at input 540, throughinterface channel 538, through fluidic input bore 537, through pistonchannel 536, and into conducting interface 534. Bore 438 may also beused to introduce air or other fluids into an inner volume 560, orannular space, of first piston conductor 512. In some examples, thefluid is pressurized air that is used to increase a pressure in innervolume 560, forcing first piston conductor 512 away from head-endinterface 400.

Turning from the structure of work machine 100, conductor rod 500, andhead-end interface 400 as illustrated in FIG. 5 , FIG. 6 illustrates amethod 600 involving these structures. FIG. 6 is a flowchart of arepresentative method 600 for using multi-tiered head-end interface of arod conductor rod to power a work. As shown in FIG. 6 , at step 602 atleast a proximal end of a conductor rod 500 is secured to a workmachine. For example, step 602 may be performed by connecting cylinderconductors 502, 504, and 506 to head-end interface 400 using terminalconnectors. As discussed in detail above, work machine 100, such as ahauling truck at a mining site, can include conductor rod 106 with aplurality of conductive tubes, typically made of an aluminum alloy,arranged concentrically around a longitudinal axis. Near a head 122 ofconductor rod 106 proximal to work machine 100, head-end interface 400is integrated into conductor rod 500, as reflected in FIG. 5 . Conductorrod 500 can be mounted to work machine 100 in any convenient fashiondepending on the implementation, including securing the conductor rod towork machine 100 in some situations to be stationary and in othersituations to be rotational about its longitudinal axis.

Further, in a step 604, a distal end of conductor rod 500 is connectedto a connector assembly, such as connector assembly 114 of FIG. 1 . Instep 604, piston conductors are affixed to connector assembly 114 ofFIG. 1 . For example, piston conductors 512-516 are affixed to connectorassembly 114 of FIG. 1 . Connecting cylinder conductors 502, 504, and506 to head-end interface 400 and piston conductors 512-516 to connectorassembly 114, when piston conductors 512-516 are slidably engaged tocylinder conductors 502-506 provide for a continuous electrical pathfrom a power source, through connector assembly 114, piston conductors512-516, cylinder conductors 502-506, into and through head-endinterface 400.

In step 606, work machine 100 is electrically connected to head-endinterface 400 using one or more terminal connectors and wire or cables.The head-end interface 400 is a multi-tier interface, meaning theelectrical connection to each cylinder conductor through a terminalconnector is at a different tier of head-end interface. To provide powerto work machine 100, at step 608, connector assembly 114 is connected topower rail 108 via trailing arms 116 and contactor 118.

At step 610, electrical power is delivered through the terminalconnectors into work machine 100. In some examples, trailing arms 116are conductors coupled to contactor 118, each conducting voltage andcurrent at a different electrical pole and corresponding to theconductors within conductor rod 106. The voltages are designed toservice various loads in work machine 100, including electric engine 102of work machine 100.

In step 612, a pneumatic connection is established with a bore, such asbore 438 of FIG. 5 , positioned at a longitudinal end of the head-endinterface. The connection with bore 438, in the illustrated examples,provides passage for pressurized air into cavities within conductor rod500 for providing forces to move or position arm 110 with respect tobarrel 109.

While FIGS. 1-6 illustrate a first example of head-end interface 120,FIGS. 7 and 8 depict a second example of a head-end interface 700 foruse with work machine 100. Head-end interface 700 includes structuralfeatures that enable electrical connection with conductor rod 106radially around its exterior, as well as pneumatic connection withconductor rod 106 axially through an interface end 702. Head-endinterface 700, with an interface on the circumference of conductor rod106, provides radial access for passing electrical power from conductorrod 106 to work machine 100 and enables continued electricalconductivity during rotation of conductor rod 106 around a longitudinalcentral axis YZ. FIG. 7 is a view of a portion of conductor rod 106).FIG. 8 is a longitudinal section of conductor rod 106 along the cutlines shown in FIG. 7 , revealing internal conductors, cavities, andconduits as discussed below.

Referring first to FIG. 7 , conductor rod 106 includes head-endinterface 700 connected to head 122 of barrel 109. Barrel 109 has anouter shell 703 around its exterior, which may be a conductive materialhaving mechanical rigidity, such as an aluminum alloy. In someimplementations, outer shell 703 serves as an electrical grounding pathfor conductor rod 106. Radially around its exterior, head-end interface700 includes rings of conductive material, specifically first metalliccontact 704 and second metallic contact 706. First metallic contact 704and second metallic contact 706 are connected within head-end interface700 to conductors extending longitudinally within conductor rod 106 thatcarry electrical power from power rail 108. First metallic contact 704and second metallic contact 706 function as interfaces for theelectrical power from power rail 108 to work machine 100. The exampledepicted in FIG. 7 contains two contacts as first metallic contact 704and second metallic contact 706 corresponding to two conductors withinconductor rod 106. In other examples, more or fewer conductors andcontacts may be used to correspond to the arrangement of conductorswithin conductor rod 106. For instance, a version of head-end interface700 not shown could employ one or more rings of conductive material inaddition to first metallic contact 704 and second metallic contact 706.

Separators in the form of an insulative material such as plastic arepositioned longitudinally between first metallic contact 704 and secondmetallic contact 706. First separator 708, for instance, serves as astructural interface between head-end interface 700 and head 122 ofbarrel 109, while electrically separating outer shell 703 and secondmetallic contact 706. Second separator 710 spaces first metallic contact704 from second metallic contact 706. Third separator 712 acts as anendcap for head-end interface 700, while providing insulationlongitudinally for first metallic contact 704. As shown in FIG. 7 ,third separator 712 has an annular shape and includes interface end 702having a surface 705 extending perpendicular from central axis YZ andforming a structural terminus for conductor rod 106. The insulativematerial of third separator 712 can serve to protect equipment andpersonnel from voltages present on first metallic contact 704 and secondmetallic contact 706 present farther inward longitudinally along centralaxis YZ on conductor rod 106. Thus, in some examples, first separator708, second separator 710, and third separator 712 help electricallyinsulate first metallic contact 704, and second metallic contact 706,and provide structural and mechanical form to head-end interface 700.

When installed on work machine 100, conductor rod 106 enables electricalconnection radially via one or more of first metallic contact 704 andsecond metallic contact 706. Extending around a circumference ofhead-end interface 700, first metallic contact 704 and second metalliccontact 706 of head-end interface 700 can provide a substantial surfacearea for interfacing electrical power from conductor rod 106 to workmachine 100 with a high level of conductivity. A mating mechanism (notshown) within work machine 100 can grasp or otherwise contact firstmetallic contact 704 and second metallic contact 706 around the exteriorof head-end interface 700. In addition, in some examples, first metalliccontact 704, second metallic contact 706, and the mating mechanism mayfacilitate a sliding connection. For instance, in implementations whereconductor rod 106 rotates about central axis YZ, such as to enablevertical movement of trailing arms 116, first metallic contact 704 andsecond metallic contact 706 permit head-end interface 700 to stay inelectrical contact with a mating mechanism while the rotation occurs,ensuring the continued delivery of electrical power to work machine 100.

FIG. 7 further illustrates a pneumatic interface within interface end702 of third separator 712. In general, third separator 712 includes oneor more openings through interface end 702 in which pressurized air maybe passed axially to the inside of conductor rod 106 from a compressorwithin work machine 100. The pressurized air may be used as an energysource to drive mechanical movement of conductor rod 106. In someexamples, the pressurized air can be used in a pneumatic control systemto force nested conductor tubes within conductor rod 106 to move axiallywith respect to each other, such as when arm 110 is forced to slideaxially with respect to barrel 109. In other examples, the pressurizedair can be routed through conductor rod 106 to be used near or beyondtip 124, such as to provide force relating to contactor 118 on powerrail 108. As embodied in FIG. 7 , the openings for pressurized airthrough interface end 702 include center bore 714, first middle bore716, second middle bore 718, first outer bore 720, and second outer bore722, which are explained below with respect to FIG. 8 . Center bore 714is at an axial center of head-end interface 700 along the central axisYZ. In some examples, such as shown in FIG. 7 , first middle bore 716and second middle bore 718 are positioned a first radial distanceoutward from the central axis YZ, while first outer bore 720 and secondouter bore 722 are located a second radial distance outward from thecentral axis YZ, where the second radial distance is greater than thefirst radial distance.

FIG. 8 , which is a longitudinal section of conductor rod 106 in FIG. 7, illustrates the internal structure of barrel 109 and head-endinterface 700. FIG. 8 reveals that the contactor rings on the exteriorof head-end interface 700, which are first metallic contact 704 andsecond metallic contact 706, are annular-shaped rings or discs thatconnect with a respective tubular conductor and extend radially for aportion through the interior of head-end interface 700. For instance, afirst barrel conductor 802 is a metallic material such as an aluminumalloy in the shape of a tube or a hollow cylinder centered axially alongthe central axis YZ. A first barrel cavity 804 is defined by an innersurface 805 of first barrel conductor 802. First barrel conductor 802 isa central conductor within barrel 109 and, in the example of FIG. 8 ,terminates longitudinally in the direction of Y of central axis YZ axisinto first metallic contact 704. First barrel conductor 802 and firstmetallic contact 704 are configured to be substantially orthogonal toeach other, and together provide a conductive path for electricalvoltage radially from an interior to an exterior of conductor rod 106.First metallic contact 704 extends from first barrel conductor 802 to anouter surface 835 of head-end interface 700, as shown, where mechanicaland electrical connection can be made to work machine 100. In oneexample, first barrel conductor 802 and first metallic contact 704conduct +1500 VDC from within barrel 109 to first metallic contact 704at an exterior of conductor rod 106. In some examples, first metalliccontact 704 and first barrel conductor 802 are the same material andstructure, although they may be different substances or separate piecesconnected together. In general, first barrel conductor 802 and firstmetallic contact 704 form a shape resembling a tubular pole (firstbarrel conductor 802) arranged along central axis YZ with a flat base orendplate (first metallic contact 704) positioned along the X axis.

Similarly, second barrel conductor 806 is a conductor formed of ametallic material such as an aluminum alloy in the shape of a tube or ahollow cylinder as part of barrel 109. Second barrel conductor 806 isaxially centered along central axis YZ and concentrically positionedsurrounding first barrel conductor 802. A distance between theconcentric tubes of first barrel conductor 802 and second barrelconductor 806 results in second barrel cavity 808. Radially outsidesecond barrel conductor 806 and within an outer shell 703 of barrel 109is third barrel cavity 810. Second barrel conductor 806 terminateslongitudinally in the direction Y of the YZ axis in FIG. 8 into secondmetallic contact 706, which is substantially orthogonal with secondbarrel conductor 806. Together, second barrel conductor 806 and secondmetallic contact 706 form a conductive path for electrical voltage, suchas −1500 VDC from within barrel 109 to second metallic contact 706 at anexterior of conductor rod 106. In some examples, second metallic contact706 and second barrel conductor 806 are the same material and structure,although they may be different substances or separate componentsconnected together. As with first barrel conductor 802 and firstmetallic contact 704, second barrel conductor 806 and second metalliccontact 706 collectively form a shape resembling a tubular pole arrangedalong the central axis YZ having a flat base or endplate positionedalong the X axis.

FIG. 8 further illustrates a portion of arm 110 nested within outershell 703 and barrel 109. Specifically, arm 110 includes first armconductor 812 arranged axially along the central axis YZ. First armconductor 812 is a conductor made of a metallic material such as analuminum alloy and has a tubular or hollow cylinder shape. An outerdiameter of first arm conductor 812 is sized so that first arm conductor812 contacts an inner surface of first barrel conductor 802 and yet canslide axially into the annular first barrel cavity 804. The tubularconfiguration of first arm conductor 812 leads to a central arm cavity814 along the axial center of first arm conductor 812. The combinationof central arm cavity 814 and first barrel cavity 804 provides a centralpassageway of open space longitudinally within conductor rod 106.Similarly, arm 110 includes a second arm conductor 816 as a tube-shapedconductive element arranged concentrically around first arm conductor812. Second arm conductor 816, which may also be an aluminum alloy oranother material having an acceptable level of electrical conductivityand mechanical resilience, has an outer diameter sufficient to causecontact with an inner diameter of second barrel conductor 806. At thesame time, the sizing of second arm conductor 816 and second barrelconductor 806 are such that second arm conductor 816 may freely slidewithin second barrel conductor 806 and move into second barrel cavity808 during retraction of arm 110.

Finally, in the example of FIG. 8 , arm 110 includes third arm conductor818. Third arm conductor 818 is also a conductive material such as analuminum alloy and is sized to slide in contact within an inner diameterof outer shell 703. In a position of retraction for arm 110, third armconductor 818 will slide into third barrel cavity 810 within barrel 109.The axial ends of first arm conductor 812, second arm conductor 816, andthird arm conductor 818 leading into barrel 109 are respectively coveredby first arm cap 820, second arm cap 822, and third arm cap 824. Firstarm cap 820 essentially fills the radial diameter of first barrel cavity804 within first barrel conductor 802 but for central arm cavity 814.Second arm cap 822 substantially fills the radial distance of secondbarrel cavity 808 (i.e., the distance between the outer diameter offirst barrel conductor 802 and the inner diameter of second barrelconductor 806). Third arm cap 824 substantially fills the radialdistance of third barrel cavity 810 (i.e., the distance between theouter diameter of second barrel conductor 806 and the inner diameter ofouter shell 703).

Head-end interface 700 further includes a series of bores andpassageways through which pressurized air may be delivered within atleast barrel 109. As arm 110 is axially slidable within barrel 109,pressurized air from a pneumatic control system may provide forces tocause the extension or retraction of arm 110. As noted above, thepressurized air is provided to conductor rod 106 from work machine 100through interface end 702. As shown in FIG. 8 , center bore 714 passesfrom interface end 702 along the central axis YZ and into first barrelcavity 804. As first barrel cavity 804 and central arm cavity 814 adjoineach other in forming a central passageway through conductor rod 106,center bore 714 serves to feed pressurized air from work machine 100into barrel 109 and along the length of arm 110, possibly to tip 124.First outer bore 720 and second outer bore 722 provide passageways forpressurized air to enter third barrel cavity 810 of barrel 109. In someexamples, the pressurized air within third barrel cavity 810 provides anaxial force against third arm cap 824 that, depending on other pneumaticforces acting on arm 110, may affect the movement of arm 110 axiallywithin barrel 109.

Likewise, first middle bore 716 and second middle bore 718 (not shown inFIG. 8 ) provide passageways for pressurized air to enter second barrelcavity 808 of barrel 109. First middle bore 716 and second middle bore718 in some implementations are in the same plane as center bore 714,first outer bore 720, and second outer bore 722, namely, thelongitudinal section shown in FIG. 8 . As illustrated in FIG. 8 ,however, in other implementations first middle bore 716 and secondmiddle bore 718 are offset angularly about the central axis YZ withrespect to first outer bore 720 and second outer bore 722. In someexamples, first middle bore 716 and second middle bore 718 are eachabout 90 degrees apart from first outer bore 720 and second outer bore722, although other angles are within the scope of this disclosure. Thisangular offset may, for instance, provide room between each of the boresalong interface end 702 for connection of equipment to supply thepressurized air.

In some examples, one or more of first metallic contact 704, secondmetallic contact 706, first separator 708, second separator 710, andsecond separator 710 include ringed conduits to provide passageways forpressurized air circumferentially around the central axis Y-Y from whereaxial bores radially enter interface end 702. For instance, at the upperright in FIG. 8 , second outer bore 722 provides access for pressurizedair into conductor rod 106 that leads into third barrel cavity 810.Third ringed conduit 832 intersects with second outer bore 722 and formsa pathway (not shown) of circular or similar shape for the pressurizedair to travel about axis Y-Y (i.e., in the X-Z plane). At the lowerright in FIG. 8 , third ringed conduit 832 intersects first outer bore720. Similarly, first middle bore 716 extends longitudinally parallel tocentral axis YZ and intersects with first ringed conduit 828 withinthird separator 712. From first ringed conduit 828, the pressurized aircan pass through internal middle bore 826 and into second barrel cavity808. Second ringed conduit 830 provides an additional example of apneumatic connection or pathway made from a radial position of firstouter bore 720 and second outer bore 722 circumferentially aroundhead-end interface 700 (i.e., in the X-Z plane). The various ringedconduits may be made as grooves within longitudinal sides of firstmetallic contact 704 or second metallic contact 706 or within firstseparator 708, second separator 710, or third separator 712. Moreover,additional bores connecting from one or more of the ringed conduits maybe present within head-end interface 700 to provide other paths forpressurized air to enter any one of first barrel cavity 804, secondbarrel cavity 808, or third barrel cavity 810.

In addition, although discussed in terms of pneumatic control, one ormore of center bore 714, first middle bore 716, second middle bore 718,first outer bore 720, or second outer bore 722 could be used tofacilitate the passage of signals into conductor rod 106. For instance,conductor rod 106 could contain electrical sensors or controls, such asfor monitoring its position, temperature, or movement, and signalsrelating to those activities may be passed through interface end 702 viathe one or more bores. The signals could be passed optically usingline-of-sight arrangements, such as through center bore 714, firstbarrel cavity 804, and central arm cavity 814, or they could be passedthrough wires, optical fibers, or other media. Additional orificeswithin interface end 702 and through head-end interface 700 could beadded to facilitate the passage of electrical or optical signals asdesired without departing from the principles discussed.

Therefore, the example head-end interface 700 in FIGS. 7 and 8 providesa structure configured to enable work machine 100 to have an electricalconnection radially with conductor rod 106 and a pneumatic connectionaxially. The electrical connection can provide sufficient power tooperate electric engine 102, while the pneumatic connection can deliverpressurized air to selective cavities within conductor rod 106 to causeat least axial movement of arm 110 with respect to barrel 109. Moreover,head-end interface 700 provides a configuration sufficient, if desiredfor the implementation, for conductor rod 106 to rotate about itslongitudinal axis while maintaining electrical connection betweenhead-end interface 700 and work machine 100.

Turning from the structure of work machine 100, conductor rod 106, andhead-end interface 700 as illustrated in FIGS. 7 and 8 to a method 900for powering a work machine from a moveable conductive rod. As shown inFIG. 9 , at step 902 at least a proximal end of a rod of concentricallyarranged tubular conductors is secured to a work machine. As discussedin detail above, work machine 100, such as a hauling truck at a miningsite, can include conductor rod 106 with a plurality of conductivetubes, typically made of an aluminum alloy, arranged concentricallyaround a longitudinal axis. Near a head 122 of conductor rod 106proximal to work machine 100, head-end interface 700 is integrated intoconduction rod 106, as reflected in FIGS. 1, 7, and 8 . Conductor rod106 can be mounted to work machine 100 in any convenient fashiondepending on the implementation, including securing the conductor rod towork machine 100 in some situations to be stationary and in othersituations to be rotational about its longitudinal axis.

Further, in a step 904, an electrical connection is established with twoor more ringed contacts positioned around the circumference of ahead-end interface on the conductor rod. As implemented in the exampleof FIG. 7 , head-end interface 700 includes first metallic contact 704and second metallic contact 706 around the outside of conductor rod 106.According to step 904, connection is made between one or both of firstmetallic contact 704 and second metallic contact 706 and compatiblecontacts within work machine 100 at the radial sides of head-endinterface 700. In step 906, a pneumatic connection is established withtwo or more bores positioned at a longitudinal end of the head-endinterface. The two or more bores may include center bore 714, firstmiddle bore 716, second middle bore 718, first outer bore 720, or secondouter bore 722, for example. The connection with these bores, in theillustrated examples, provides passage for pressurized air into cavitieswithin conductor rod 106 for providing forces to move or position arm110 with respect to barrel 109.

In subsequent steps, the work machine is powered with electricity, andthe conductor rod is power with pressurized air. Specifically, in step906, a distal end of the rod is connected to a power rail providingelectrical power. As shown in FIG. 1 , the connection between contactor118 and power rails 108 provides access for work machine 100 toelectrical power present on power rails 108. In step 910, the electricalpower is delivered through the two or more ringed contacts on theconductor rod to the electrical connection. As shown in part in FIG. 8 ,concentric conductor tubes convey the electrical power from power rail108 through arm 110 and barrel 109 to the series of annular ordisk-shaped terminals, first metallic contact 704 and second metalliccontact 706. From those contacts, the electrical power may pass througha connection into work machine 100. In a step 912, pressurized air isdelivered from the work machine through the pneumatic connection to thetwo or more bores. In some examples, the delivery of pressurized airthrough interface end 702 and into head-end interface 700 provides ameans under a pneumatic control system to manipulate the position of atleast arm 110. Accordingly, head-end interface 700 can provide aninterface that enables radial attachment for electrical power and axialattachment for pneumatic power between conductor rod 106 and workmachine 100, enabling the efficient powering of work machine 100 andconductor rod 106 including the flexibility to permit rotation ofconductor rod 106 about its longitudinal axis as desired.

Those of ordinary skill in the field will also appreciate that theprinciples of this disclosure are not limited to the specific examplesdiscussed or illustrated in the figures. For example, while conductorrod 106 for FIGS. 7 and 8 are illustrated with two conductors, three ormore conductors may be employed following the principles explained inthe present disclosure. In addition, the principles disclosed are notlimited to implementation on a work machine. Any moving vehicle derivingelectrical power from a ground-based conductor rail could benefit fromthe examples and techniques disclosed and claimed.

INDUSTRIAL APPLICABILITY

The present disclosure provides a system for a moving machine having aconductor rod configured to convey multiple poles of electrical energyfrom an energized rail to the moving machine, where the conductor rodhas tubular conductors successively arranged concentrically around alongitudinal axis. As noted above with respect to FIGS. 4 and 5 , amulti-tier head-end interface can be used to provide some technicalbenefits. For example, having tiers 410-416 provide for the ability toconnect electrical connectors onto head-end interface 400 whilemaximizing the distance between adjacent threaded members. For example,threaded member 408A and 406A are proximate to each other radially alongthe X axis. If on the same plane along the X axis, threaded member 408Amay be in a proximate distance that may make connecting electricalconnector 434 onto threaded member 408A difficult because of the closecontact between threaded member 408A and threaded member 406A. Further,if threaded member 408A and 406A are proximate to each other radiallyalong the X axis, the close proximate distance may increase aprobability of a short between threaded member 408A and 406A. Forexample, if on the same tier (or plane), electrical connector 434 may bein close proximity to electrical connector 436 affixed to threadedmember 406A. Because threaded members 408A and 406A may each be carryingelectrical current from a power source, the close proximity may increasethe probably of an electrical short, potentially causing safety issuesand equipment damage. Electrical connectors 434 and 436 provideelectrical power received from threaded members 408A and 406A,respectively, to load 437.

The use of tiers 710-716 provides a degree of separation from proximatethreaded members along the Z axis. Although threaded members 408A and406A may be in close proximity along the X axis, threaded member 408A isseparated from threaded member 406A along the Z axis by height C. Theincreased distance can reduce the effort to connect electrical connector434 onto threaded member 408A because of the distance C between threadedmember 408A and threaded member 406A. Further, because of the distance Cbetween threaded member 408A and threaded member 406A, the probabilityof an electrical short between threaded members 408A and 406A may bereduced. Thus, the use of a multi-tiered head-end interface 400 providesdistance between adjacent threaded members without requiring an increaseof a diameter of the base, tier 416.

Unless explicitly excluded, the use of the singular to describe acomponent, structure, or operation does not exclude the use of pluralsuch components, structures, or operations or their equivalents. As usedherein, the word “or” refers to any possible permutation of a set ofitems. For example, the phrase “A, B, or C” refers to at least one of A,B, C, or any combination thereof, such as any of: A; B; C; A and B; Aand C; B and C; A, B, and C; or multiple of any item such as A and A; B,B, and C; A, A, B, C, and C; etc.

While aspects of the present disclosure have been particularly shown anddescribed with reference to the embodiments above, it will be understoodby those skilled in the art that various additional embodiments may becontemplated by the modification of the disclosed machines, systems andmethods without departing from the spirit and scope of what isdisclosed. Such embodiments should be understood to fall within thescope of the present disclosure as determined based upon the claims andany equivalents thereof.

What is claimed is:
 1. An apparatus, comprising: a substantially rigidouter tube with a first end and a second end, the outer tube having afirst outer surface, a first inner surface defining a first diameter, afirst inner space defined by the first inner surface, and an axisextending substantially centrally through the inner space from the firstend to the second end; a first cylindrical conductor disposedconcentrically around the axis, at least in part, within the first innerspace, the first conductor having a second outer surface and a secondinner surface, wherein the second outer surface defines a seconddiameter less than the first diameter; a second cylindrical conductordisposed concentrically around the axis, at least in part, within thefirst inner space, the second conductor having a third outer surface anda third inner surface defining a second inner space, wherein the thirdouter surface defines a third diameter less than the second diameter;and a head-end interface, comprising: a first tier comprising a firstplanar surface extending substantially perpendicular to the axis, and afirst substantially cylindrical outer surface extending from the firstplanar surface, the first substantially cylindrical outer surfacedefining: a fourth diameter, and a first height as measured from thefirst planar surface to a base of the head-end interface, wherein theouter tube is affixed to the first tier at an internal surface of thehead-end interface using a first set of terminal connectors; a secondtier comprising a second planar surface extending substantiallyperpendicular to the axis, and a second substantially cylindrical outersurface extending from the second planar surface, the secondsubstantially cylindrical outer surface defining: a fifth diameter, anda second height as measured from the second planar surface to the firstplanar surface, wherein the first conductor is affixed to the secondtier at the internal surface of the head-end interface using a secondset of terminal connectors; and a third tier comprising a third planarsurface extending substantially perpendicular to the axis, and a thirdsubstantially cylindrical outer surface extending from the third planarsurface, the third substantially cylindrical outer surface defining: asixth diameter, and a third height as measured from the third planarsurface to the second planar surface, wherein the second conductor isaffixed to the third tier at the internal surface of the head-endinterface using a third set of terminal connectors.
 2. The apparatus ofclaim 1, wherein the fourth diameter is greater than the fifth diameterand the fifth diameter is greater than the sixth diameter.
 3. Theapparatus of claim 1, wherein the first height, the second height, andthe third height are substantially similar.
 4. The apparatus of claim 1,further comprising a first electrical connector connected at the outersurface of the head-end interface to at least one of the second set ofterminal connectors, the first electrical connector being configured todirect a first electrical potential to a load.
 5. The apparatus of claim4, further comprising a second electrical connector connected at theouter surface of the head-end interface to at least one of the third setof terminal connectors the second electrical connector being configuredto direct a first electrical potential to a load.
 6. The apparatus ofclaim 5, further comprising a third electrical connector connected atthe outer surface of the head-end interface to at least one of the firstset of terminal connectors, the third electrical connector connected toa ground to ground the rigid outer tube.
 7. The apparatus of claim 1,further comprising a bore through the head-end interface, the boreconfigured to receive pressurized air into an annular space of thehead-end interface.
 8. A head-end interface, comprising: a first tiercomprising a first planar surface extending substantially perpendicularto an axis extending substantially centrally through an inner space ofthe head-end interface from a first end of the head-end interface to asecond end of the head-end interface, and a first substantiallycylindrical outer surface extending from the first planar surface, thefirst substantially cylindrical outer surface defining: a firstdiameter, and a first height as measured from the first planar surfaceto a base of the head-end interface; a second tier comprising a secondplanar surface extending substantially perpendicular to the axis, and asecond substantially cylindrical outer surface extending from the secondplanar surface, the second substantially cylindrical outer surfacedefining: a second diameter, and a second height as measured from thesecond planar surface to the first planar surface; and a third tiercomprising a third planar surface extending substantially perpendicularto the axis, and a third substantially cylindrical outer surfaceextending from the third planar surface, the third substantiallycylindrical outer surface defining: a third diameter, and a third heightas measured from the third planar surface to the second planar surface.9. The head-end interface of claim 8, wherein: a substantially rigidouter tube disposed concentrically around the axis is affixed to thefirst tier at an internal surface of the head-end interface using afirst set of terminal connectors; a first cylindrical conductor disposedconcentrically around the axis is affixed to the second tier at theinternal surface of the head-end interface using a second set ofterminal connectors; and a second cylindrical conductor disposedconcentrically around the axis is affixed to the third tier at theinternal surface of the head-end interface using a third set of terminalconnectors.
 10. The head-end interface of claim 9, further comprising abore comprising an annular space through the head-end interface, thebore configured to receive pressurized air into an annular space of thehead-end interface.
 11. The head-end interface of claim 9, furthercomprising a fluidic input bore extending through the head-endinterface.
 12. The head-end interface of claim 11, wherein the fluidicinput bore is an annular space that extends through the head-endinterface connecting an exterior of the head-end interface with aconducting interface between an outer surface of the first cylindricalconductor and an inner surface of a piston conductor slidably engagedwith the first cylindrical conductor.
 13. The head-end interface ofclaim 12, wherein the fluidic input bore is used to input liquidmetallic alloy comprising GALINSTAN.
 14. The head-end interface of claim11, wherein the fluidic input bore is configured to receive gasescomprise air, nitrogen, helium, or sulfur hexafluoride.
 15. The head-endinterface of claim 9, further comprising: a first electrical connectorconnected at an outer surface of the head-end interface to at least oneof a fourth set of terminal connectors, the first electrical connectorbeing configured to direct a first electrical potential to a load; asecond electrical connector connected at the outer surface of thehead-end interface to at least one of a fifth set of terminalconnectors, the second electrical connector being configured to direct asecond electrical potential to the load; and a third electricalconnector connected at the outer surface of the head-end interface to atleast one of a sixth set of terminal connectors, the third electricalconnector connected to a ground to ground the rigid outer tube.
 16. Awork machine, comprising: an electric engine; a battery; tractiondevices configured to cause movement of the work machine when powered bythe electric engine; a conductor rod configured to convey electricalenergy to the work machine during a movement of the work machine, theconductor rod having a first end and a second end, the conductor rodcomprising: a rigid outer tube having an outer diameter and alongitudinal center defining an axis between the first end and thesecond end; and a plurality of tubular conductors successively arrangedconcentrically around the axis and separated, at least in part, by air;a head-end interface at the first end of the conductor rod, wherein thefirst end of the conductor rod is attached to an internal surface of thehead-end interface, the head-end interface comprising: a first tier atan outer surface of the head-end interface, the first tier having afirst diameter as measured through a central axis of the head-endinterface and a first height as measured from a base of the head-endinterface, wherein the rigid outer tube is affixed to the first tier atthe internal surface of the head-end interface using a first set ofterminal connectors; a second tier at the outer surface of the head-endinterface, the second tier having a second diameter smaller than thefirst diameter as measured through an axial length of the head-endinterface and a second height as measured from the base of the head-endinterface, wherein a first tubular conductor of the plurality of tubularconductors is affixed to the second tier at the internal surface of thehead-end interface using a second set of terminal connectors, whereinthe second height is greater than the first height; and a third tier atthe outer surface of the head-end interface, the third tier having athird diameter smaller than the first diameter and the second diameteras measured through the axial length of the head-end interface and athird height as measured from the base of the head-end interface,wherein a second tubular conductor of the plurality of tubularconductors is affixed to the third tier at the internal surface of thehead-end interface using a third set of terminal connectors, wherein thethird height is greater than the first height and the second height. 17.The work machine of claim 16, further comprising: a first electricalconnector connected at the outer surface of the head-end interface to atleast one of the second set of terminal connectors to provide a firstelectrical potential to a load; a second electrical connector connectedat the outer surface of the head-end interface to at least one of thethird set of terminal connectors to provide a second electricalpotential to the load; and a third electrical connector connected at theouter surface of the head-end interface to at least one of the first setof terminal connectors, the third electrical connector connected to aground to ground the rigid outer tube.
 18. The work machine of claim 16,further comprising a bore through the head-end interface, the boreconfigured to receive pressurized air into an annular space of a firsttubular conductor of the plurality of tubular conductors.
 19. The workmachine of claim 16, further comprising a fluidic input bore extendingthrough the head-end interface, the fluidic input bore formed byremoving a terminal connector used to affix the first tubular conductorto the head-end interface, wherein the fluidic input bore is configuredto receive a liquid metallic alloy into a conducting interface betweenan outer surface of a first tubular conductor of the plurality oftubular conductors and an inner surface of a piston conductor slidablyengaged with the first tubular conductor of the plurality of tubularconductors.
 20. The work machine of claim 19, wherein the fluidic inputbore is further configured to receive gases comprise air, nitrogen,helium, or sulfur hexafluoride or allow for removal of a fluid to createa partial vacuum.